The memo says then-FBI Deputy Director Andrew McCabe testified he believed a court would not have approved the warrant for the surveillance of Trump advisor Carter Page were it not for information that was included in a dossier assembled by former British spy Christopher Steele.

But — and this is a big but — it is unclear from the memo whether the information about Page existed elsewhere. Only that the information was in the dossier. So the FBI could have gotten the information from different sources and methods than Steele did, and reached the same conclusion.

The 35-page so-called Steele dossier contains a number of pieces of raw intelligence about the alleged behavior of Trump campaign officials and Trump himself with regards to Russia. It is unclear how many of them have been corroborated by intelligence officials today.

But Page himself has admitted meeting with Russians during a trip to Moscow in the summer of 2016, months before the presidential election. He also gave a speech during the trip about how Trump would reset U.S.-Russia relations. The speech was posted on YouTube.

In their application for the warrant to the Foreign Intelligence Surveillance Court, DOJ officials did not say the Steele dossier was funded in part by the Hillary Clinton campaign and the Democratic National Committee, which some of them knew at the time.

The Free Beacon has publicly distanced itself from Steele and his dossier, which was produced after Fusion GPS completed its primary work for the right-leaning publication. The Clinton folks didn't get involved until near the end of the GOP primaries, when it was clear Trump would be the nominee.

Steele, however, did not like Trump, and he told a Justice Department official he was "desperate that Donald Trump not get elected and was passionate about him not being president."

But Steele also had a record of providing credible intelligence to American officials that predated this dossier, which is why FBI officials took the information contained in the dossier seriously. And there's no evidence that his political feelings influenced the quality of his work. Intelligence officers are trained not to let their personal biases color their assessments.

The biggest so-called bombshell in the memo is that when the FISA court considered the warrant application targeting Page, it wasn't told that Steele didn't like Trump or that Democrats had funded the last half of Steele's investigation, which included salacious and unconfirmed allegations about Trump.

But the memo prepared by House Intelligence Committee Chairman Devin Nunes presumes that the Steele dossier, and therefore Steele himself, were critical parts of the warrant application. And that is not clear at all.

We don't know what other evidence was included in the warrant application. FISA applications are usually at least 30 pages long, and often much longer. The part of the Steele dossier that mentions Page is one page long.

There may be no good answer as to why the information about Steele was left off the warrant application, but the answer could easily be that FBI officials didn't think it was relevant because the dossier wasn't relevant.

Trump and Nunes would like people to believe that it was left out because officials at Justice Department were in league for Clinton. But it could just as easily be that the FBI had used its own sources and methods to learn about Page's trip to Moscow, and the fact that this was mentioned in the Steele dossier was just a minor detail.

What's more, we'll never know whether having the extra details about Steele's backers would have changed the ruling of the judge who approved the warrant. FISA courts are incredibly secretive, and their proceedings are classified

In the meantime, dueling statements were flying across Washington on Friday, and the implications of the memo's contents on the president and on the FBI were not yet clear. To read a roundup of reactions, click here.

Correction: Paul Singer is a financial backer of the Washington Free Beacon, which was the first to hire Fusion GPS to perform GOP primary research.